PHP验证码是很常见的应用 下面是一段封装好的类库 方便以后使用
总结一下核心函数： imagecreate 创建图像; imagecolorallocate 为图像上色 imagerectangle 创建矩形 imagestring 画字符串 imageline 生成干扰线 imagejpeg 生成JPEG格式 imagedestroy 催婚图像
PHP验证码类
<?php
session_start ( ) ;
class checkImage {
private $config ;
private $im ;
private $str ;
function __construct ( ) {
$this -> config [ 'width' ] = 50 ;
$this -> config [ 'height' ] = 20 ;
$this -> config [ 'vcode' ] = "vcode" ;
$this -> config [ 'type' ] = "default" ;
$this -> config [ 'length' ] = 4 ;
$this -> config [ 'interfere' ] = 10 ;
$this -> str [ 'default' ] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" ;
$this -> str [ 'string' ] = "abcdefghijklmnopqrstuvwxyz" ;
$this -> str [ 'int' ] = "0123456789" ;
}
public function init ( $config = array ( ) ) {
if ( ! empty ( $config ) && is_array ( $config ) ) {
foreach ( $config as $key => $value ) {
$this -> config [ $key ] = $value ;
}
}
}
public function create ( ) {
if ( ! function_exists ( "imagecreate" ) ) {
return false ;
}
$this -> createImage ( ) ;
}
private function createImage ( ) {
$this -> im = imagecreate ( $this -> config [ 'width' ] , $this -> config [ 'height' ] ) ;
imagecolorallocate ( $this -> im , 255 , 255 , 255 ) ;
$bordercolor = imagecolorallocate ( $this -> im , 0 , 0 , 0 ) ;
imagerectangle ( $this -> im , 0 , 0 , $this -> config [ 'width' ] - 1 , $this -> config [ 'height' ] - 1 , $bordercolor ) ;
$this -> createStr ( ) ;
$vcode = $_SESSION [ $this -> config [ 'vcode' ] ] ;
$fontcolor = imagecolorallocate ( $this -> im , 46 , 46 , 46 ) ;
for ( $i = 0 ; $i < $this -> config [ 'length' ] ; $i ++ ) {
imagestring ( $this -> im , 5 , $i * 10 + 6 , rand ( 2 , 5 ) , $vcode [ $i ] , $fontcolor ) ;
}
$interfere = $this -> config [ 'interfere' ] ;
$interfere = $interfere > 30 ? "30" : $interfere ;
if ( ! empty ( $interfere ) && $interfere > 1 ) {
for ( $i = 1 ; $i < $interfere ; $i ++ ) {
$linecolor = imagecolorallocate ( $this -> im , rand ( 0 , 255 ) , rand ( 0 , 255 ) , rand ( 0 , 255 ) ) ;
$x = rand ( 1 , $this -> config [ 'width' ] ) ;
$y = rand ( 1 , $this -> config [ 'height' ] ) ;
$x2 = rand ( $x - 10 , $x + 10 ) ;
$y2 = rand ( $y - 10 , $y + 10 ) ;
imageline ( $this -> im , $x , $y , $x2 , $y2 , $linecolor ) ;
}
}
header ( "Pragma:no-cachern" ) ;
header ( "Cache-Control:no-cachern" ) ;
header ( "Expires:0rn" ) ;
header ( "content-type:image/jpegrn" ) ;
imagejpeg ( $this -> im ) ;
imagedestroy ( $this -> im ) ;
exit ;
}
private function createStr ( ) {
if ( $this -> config [ 'type' ] == "int" ) {
for ( $i = 1 ; $i <= $this -> config [ 'length' ] ; $i ++ ) {
$vcode .= rand ( 0 , 9 ) ;
}
$_SESSION [ $this -> config [ 'vcode' ] ] = $vcode ;
return true ;
}
$len = strlen ( $this -> str [ $this -> config [ 'type' ] ] ) ;
if ( ! $len ) {
$this -> config [ 'type' ] = "default" ;
$this -> create_str ( ) ;
}
for ( $i = 1 ; $i <= $this -> config [ 'length' ] ; $i ++ ) {
$offset = rand ( 0 , $len - 1 ) ;
$vcode .= substr ( $this -> str [ $this -> config [ 'type' ] ] , $offset , 1 ) ;
}
$_SESSION [ $this -> config [ 'vcode' ] ] = $vcode ;
return true ;
}
}
$v = new checkImage ( ) ;
//$config['width'] = 50; //验证码宽
//$config['height'] = 20; //验证码高
//$config['vcode'] = "vcode"; //检查验证码时用的SESSION
//$config['type'] = "int"; //验证码展示的类型default:大写字母,string:小写字母,int:数字
//$config['length'] = 2; //验证码长度
//$config['interfere']= 10; //干扰线强度,范围为1-30,0或空为不起用干扰线
//$v->init($config); //配置
$v -> create ( ) ;
?>
<SCRIPT LANGUAGE="JavaScript">
<!--
function reloadcode(){
var d = new Date();
document.getElementById('safecode').src="./vcode.php?t="+d.toTimeString()
}
//-->
</SCRIPT>
<img src="vcode.php" id="safecode" onclick="reloadcode()">